Dzhokar Tsarnaev has been charged with the Boston Marathon bombings. He is recovering from a neck wound. / Bloomberg

by Michael Winter, USA TODAY

by Michael Winter, USA TODAY

Boston Marathon bombing suspect Dzhokhar Tsarnaev had no gun when police fired on a boat where he had been hiding Friday before his capture, federal law enforcement officials told The Washington Post.

The report undercuts initial accounts that the 19-year-old university student was heavily armed, had shot at police and possibly had an explosive device.

The FBI would not tell the Post what prompted officers to fire dozens of rounds at the covered boat in a Watertown, Mass., driveway Friday night. Tsarnaev was wounded when he surrendered, but the FBI would also not say whether he was shot during the finale or the shootout with authorities that killed his 26-year-old brother, Tamerlan.

Some authorities said at the time the wound may have come from a suicide attempt. The Post report does not indicate whether Tsarnaev may have had a knife when he surrendered.

Dzhokhar Tsarnaev is recovering from a neck wound in a Boston hospital and was in fair condition Wednesday. Monday, he was charged with the April 15 double blasts that killed three people and injured more than 260. He was also charged with killing Massachusetts Institute of Technology police officer Sean Collier, who was shot in his patrol car late Thursday. Collier was buried Wednesday.

Although the FBI was in charge of the Watertown scene, the police presence included Massachusetts State Police, local departments and the transit agency. One law enforcement official described the final chaotic 30 minutes as the "fog of war," saying that an accidental shot may have caused other officers to begin firing.

"Law enforcement was placed in an extraordinarily dangerous situation," FBI spokesman Paul Bresson told the Post. "They were dealing with an individual who is alleged to have been involved in the bombings at the Boston Marathon. As if that's not enough, there were indications of a carjacking, gunfire, an ambushed police officer and bombs thrown earlier. In spite of these extraordinary factors, they were able to capture this individual alive with no further harm to law enforcement. It was a tremendously effective outcome under dire circumstances."